Karl III Philip (Charles Philip), Elector Palatine of the Rhine (Kurfürst von der Pfalz), 1716-1742: born 4 November 1661, the seventh of seventeen children of Philipp Wilhelm, Elector Palatine, and succeeded his brother Johann Wilhelm as elector in 1716.

The period of his rule was one of oppression for the Mennonites. Because of their religious separatism they were made to endure much hardship. Even the confirmation of their civic privileges, which the Mennonites asked for in 1717, was granted only after much trouble. Karl Philip finally ordered that they should be tolerated as before, without, however, being permitted to have public church buildings. For the confirmation of this concession the court council demanded payment of 1,500 florins, as Philipp Wilhelm had allegedly required in 1686 upon assuming the government. Although this assumption was proved an error, the government years later, in 1730, when the coffers were empty, insisted that the Mennonites pay the sum. Great hardship came to the Mennonites by the application of the right of redemption against them. This law permitted a Catholic, Lutheran, or Calvinist to "redeem" any piece of land from an Anabaptist (as Mennonites then were contemptuously called) just by paying to him the purchase price without regard to the previous legal purchase of this property or any improvement in value since the original purchase. One particularly serious case happened in 1726 (with a certain Landes as victim). It was only after a long struggle that in 1737 this law was limited to three years, after which period no foreign "redemption" was any longer allowed.

Early in 1740 a new blow fell upon the Mennonites in the increase of the protection fee from 6 florins to 12 per person; the government took this step because of an alleged increase in the number of Mennonites. In spite of repeated petitions and the intervention of the noble owners of the land on their behalf, the Mennonites had to pay this amount until Karl Theodore became elector. A number of letters written to Amsterdam by Hans Burckholder and other Mennonite leaders in the Palatinate and now found in the Mennonite Archives of Amsterdam give detailed information about these difficulties.

Karl III Philip died 31 December 1742 and with his death the Palatinate-Neuburg line became extinct. He was succeeded as Elector Palatine by Karl IV Theodor (1724-1799).